Shaft coupling



W. FLEURY SHAFT COUPLING Feb. 1, 1938.

Filed Sept. 18, 19-36 INA/ENTOR m BY AT RNEYS Patented Feb. 1 1938UNITED STATES PATENT OFFICE 1 Societe Anonyme Adolphe Sa'urer,

Arbon,

Switzerland, a corporation of Svvitzerl'ami Application September l8,1936, Serial No. 101,357 In Germany May 9, 1936 2 Claims. ((31. c r-25)In the operation of internal combustion en gines, in which the fuel isinjected into the combustion chamber of the engine, and which arerequired to have a wide range of speed variation, as in the case ofDiesel engines in automotive use, it is desirable, in order to assuresmooth operation, that the instant ;of beginning injection of the fuelshould be advanced or retarded in accordance with the increase ordecrease of the speed of operation. Attempts have been made heretoforetoprovide means whereby the injection of the fuel can be given a lead or alag as determined by the variation in speed of operation of the engine,but thusfar, so far as known, the mechanism devised for the purpose hasbeen complicated, unwieldy and requiring constant supervision tomaintain certainty in operation. These objections have been overcome bythe present invention in which a servo-piston which is movablelongitudinally ,under the control of a centrifugal governor and, beingalso capable of rotation, is coupled to a driving gear of the injectionpump, is in such operative relation-with the cylinder of theservo-piston, which rotates with a shaft of the engine, that through therela.

tive longitudinal movement of the piston andcylinder a relative lead orlag in the rotation of the piston and therefore of the. driving gear ofthe injection pump, with respect to the rotation of the cylinder and itsdriving shaft, and a lead or lag of the speed of rotation'of the drivinggear of the )7 injection pump is effected. The improved mecha-.

nism is compact in design, takes up little space and is very reliable inoperation andas well is at all times thoroughly lubricated by thepressure feed oil which, under the control of the centrifugal-governor,effects the displacement of the servo-piston.

The invention will be more fully explained hereinafter with reference tothe-accompanying drawing in which it is illustrated, and in which:

Figure 1 is a view in longitudinal section of a mechanism which embodiesthe invention.

Figure 2 is a view in transversesection on the plane indicated by thebroken line 2-2 of Figure 1, and v a Figure 3 is a detail viewwinelevation of the device by which the interconnection between theservo-piston rod and the servo-cylinder is effected.

In Figure 1 there is shown at I a gear from which is driven theinjection pump. The latter may be of any usual or suitable constructionand need not be shown herein. The gear I is shown as secured to theflange 2 of the servo-cylinder 3 which is mounted for rotation in abearing sleeve 4 which maylform part of the engine housing 5.

. A fluid, preferably lubricating oil, is supplied under pressure from asuitable source to the interior of the sleeve 6 by an oil feed pipe 6.It is deliv- ,5 ered to a longitudinal channel I formed in the innersurface of the sleeve I and thence'to an annular groove 8. formed in theinner surface of the sleeve 4 near one end. The left hand end of thechamber within the sleeve 4 is closed by a 10 closure head 9 which isprovided on its outer face with brackets II) in the outer ends ofwhichare pivotally mounted, as at II, the bell crank levers) I4 whichsupport on their horizontal arms centrifugal weights .I3-and have theends of their 15 other arms forked, as at I 5, to engage a transversepin I6 of a control rod 11, the two centrifugal weights 13 beingconnected-by a spring 12 as usual. It, will be understood that thecentrifugal governor thus described rotates with the driving gear I ofthe injection pump and that as the speed increases the centrifugalweights fly outward and the control rod I1 is moved to the right,

while as the speed of rotation of the pump dei creases the centrifugalweights move toward the axis of revolution and the control rod I'I movesto the left.

The control rod 'I'I moves longitudinally intthe bore 9 of the hollowservo-piston rod 20, on which is mounted the servo-piston 2| adapted formovement within the servo-cylinder 3. The control rod IT is reduced indiameter for a portion of its length to form a recess I8, its end I1having a close sliding fit in the bore 19 of the piston rod 20 forming asliding control valve. The hollow piston rod 20, which is supported in abearing 22 in the closure head 9, has its recess I8 at all timesoverlapping and therefore in communication with vradial ports'25 in thetubular piston-rod, such ports being also in communication through theelongated channels 23 with the radial channels 24 and therefore throughthe annular channel 8 and the longitudinal channel I of the sleeve 4, incommunication with the oil inlet 6 from the oil pressure pump. Thehollow piston'rod 20 is also provided,"as at 21, with radial ports whichare in communication externally with the cylinder space 28 andinternally with elongated channels 26 so that as the control rod I1 ismoved to e the left the cylinder space 28 willbe placed in communicationwith the bore I9 of the hollow piston rod to the right of the slidingvalve I1 01', as the sliding valve II is moved to the right, the

' cylinder space 28 will be placed in communication with the recess I8and so, through the channels 23, the ports and the channels 24, with theannular channel 8 and the longitudinal channel 9 and the oil inlet pipe6.

The rod 20 of the servo-piston 2| is formed at the other'side of theservo-piston 2| with, an

enlarged "sleeve-like displacement member 29',

which is formed with longitudinal radial bosses in the form of sectorsof a cylinder each of which is formed on its outer face with rightangled, sharply pitched, spirally disposed threads 3| which engagecorresponding sharply pitched,

spirally arranged grooves fi e-formed in the-inner, surface of theservo-cylinder 3. The engine also the servo-cylinder 3 isfr'otated withthe shaft but, with a relative leader drag as determined by" therelative lc'angitudinal displacement of t Diston'and cylinder-. l

Within the chamber of the enlargement 29 r there is-placed a reactionspring 36 which bears or ad chargeof used pressure oil." I I at oneend'against a shoulder of the piston rod 20 and at the other end againstthe end of the driving shaft 35. The servo-cylinder 3 is itself heldwithout; capacity for longitudinal displacement within the bearingsleeve4 by a cap nut 31 and the driving shaft is held without capacityfor longitudinal displacement by engagement of thecap nut with theshoulder 38 and the closure disc4ll. Longitudinalchannels 4| areprovided inth'e hub of the shaft 35 for the dis.-

' As will be understood-the centrifugal weights |3 of the governorassume, for every speed of rotation of the'govern'or and of the gear I,a

certain definite position in which the'centrifugal weights and thespring l2 are in equilibrium.

For every speed of rotation the control valve ll,

l8 therefore also assumes a definite position.

In the position-'of-the parts shown in Figure 1 the: servo -piston *has'assumed a position corresponding to the position of the control valve H,

l1, l8 in whichthe cylinder space 28 is closed r fromcommunication andthe lubricating oil or other fluid thereinbeing'in equilibrium with thetension of the spring 26 the servo-piston 2| re mains at rest in thatposition. If then the speed of rotation of the governor is increased thecentrifugal weights -13 fly outward and thegcontrol valve I'IQII', I8 isshifted to "the right. Thereby the cylinder space ;28 is placed incommuni- -cation,through the channels 26, 21 with the recess i8 and,through the channels 25, 23, 24, I, and 1, with the pressureoil line- 6of" the oil pumps" The oil-pressure against the servo-piston 2| isthereby increased-andthe piston is moved toward the i right against thepressure of the spring-'36. The relative longitudinal movement of thepiston 2| with respect to the cylinder 3 and the' consequentrelativelongitudinal movement of the threads 2| in the grooves of the cylinder 3causes a relative rotary'displacement of the cylinder 3' and the shaft35 and a consequent leadof the shaft 35 relation to the gear aioaovo Ianism has therefore fla"verylsniall space rouireand an advance in thetime of fuel injection The movement of the piston toward the rightcontinues until the communication between the channels 25 and H! isinterrupted, when the servo-piston again assumes-{with reference to thecontrol valve ll, theposition shown in Figure 1.

When the speed of rotation of the engine decreases the cohtrol valve i1is shifted to the left in Figure 1, the cylinder space 28 is placed incommunication with the bore IQ of the piston rod through the channels 26and 21 and the pressure oil in :the 'c ylinder space 28 can then escapethrough thechannels 4|. The oil pressure being thus released the spring36 shifts the piston 2| to the left and thereby, through the connectionsdescribed above, the cylinder 3 and the engine shaft 5 are displaced ina rotary sense and a lag in'relative rotation: z Y the shaft 35 and thegear "If is 'occas on d f lag being continued until the pis to n'2l agaipoint of time, jof' the injgection" oflflfuel foilj into.

the engine cylinder.

It will be noted ithat th e actance spring 36 and theregulatingfdevicesture with the pump gear ,'the end closure Sof the cylinder 3 serving asa carrier for the cen;

-trifugal governor 12, ",the rod ll 19f LW' h. serves as a controlvalve.The improvedrnech ment, presents a minimum number'claf work'ingi' jointsand is at all times well lubricatedby the employment of lubricating: oilas"thepres sure fluid which acts upon the servo-pistonl I im as my invet n; ..t

1. In a mechanism ior changing; thej phase" relationship between adriven-shaftanda driv ing gear, the combination off-a driven shaft,"a

driving gear, a servo-cylinder rotatable withfthe j gear and spirallygrooved 'internally, a servo i piston, a displacement member rotatableand movable longitudinally with the servo-piston and spirally threadedtoengagethegrooves of the.

servo-cylinder, means to supply fluid under pres-' sure to the cylinderspace to move the piston in one direction, a reactance spring acting inopposition to the fluid pressure, acentrifugal' gov ernor,'meansactuated by the governor to con-' trol the movement of pressure. fluidto and from the cylinder space, and means whereby the servopiston iscoupledto the driven shaft to be"'roiplacement. 1 h g 2. A mechanism asdescribed in-claim Land in which an extension of the piston rod isformedtated thereby with freedom for longitudinal diswith radiallongitudinal bosses and thedriven.

shaft is forked-at its end to'embrace' and engage the piston rod,whereby the piston is ro-f" tated with capacity for longitudinaldisplacement. I

